Memory devices are typically provided as internal, semiconductor, integrated circuit devices in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), and flash memory.
Flash memory devices have developed into a popular source of non-volatile memory for a wide range of electronic applications. Flash memory devices typically use a one-transistor memory cell that allows for high memory densities, high reliability, and low power consumption. Changes in threshold voltage of the memory cells, through programming (which is often referred to as writing) of charge storage structures (e.g., floating gates or charge traps) or other physical phenomena (e.g., phase change or polarization), determine the data value of each cell. Common uses for flash memory include personal computers, tablet computers, digital cameras, digital media players, cellular telephones, solid state drives and removable memory modules, and the uses are growing.
Flash memory devices may use an n-channel field-effect transistor (nFET) for each memory cell. An nFET has a negative temperature coefficient. As such, the threshold voltage (Vt) to turn on an nFET decreases as the temperature of the nFET increases.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative methods for temperature coefficient trimming of a memory device, and apparatus to perform such methods.